The pruning of clematis does not need to be daunting. Culturally, the genus is divided into three pruning groups that relate to their different bloom times. Group 1 consists of all those species and their varieties that flower early spring; Group 2 includes the large-flowered hybrids that bloom in early summer and sometimes again in late summer; and the late-flowering species and hybrids make up Group 3.
|When to Prune|
Pruning should be carried out at the following times:
Group 1, which needs little pruning, should be pruned immediately after flowering to stimulate renewed growth.
Group 2 is best left to early spring when the new buds are beginning to swell.
Group 3 can be pruned hard at almost any time during the winter and early spring, but some may also be part pruned in late winter down to new shoots as they emerge.
|How to Prune|
Group 1 Prune after flowering only if plants become overgrown. Clematis Montana should be pruned hard with caution, because thick branches sometimes do not regenerate.
Group 2 Look for large, fat buds, which are the flowering shoots. Thin out old growth and last year’s flowering shoots down to the fat buds, and retrain these as they grow.
Group 3 Prune hard to with-in 6-12in
(15-30cm) of the ground, but some shoots may be left alone then pruned later in spring to the new shoots as they emerge.
|Twice-flowering Clematis, Group 2|
This group includes all the large-flowered doubles and singles that flower in early summer and sometimes again later. They must be pruned lightly in spring.